1. Field
The disclosure relates to a disc brake employing an electric wedge brake (EWB) system for performing a braking operation by using a wedge member and a pad.
2. Description of the Related Art
A disc brake generates braking force by pressing a friction pad against an outer surface of a disc rotating together with a wheel. The disc brake includes an electronic wedge brake (EWB) that presses a friction pad against a disc by using a sliding type wedge member. For instance, the wedge member presses the friction pad against the disc while moving along an oblique side by a driving device.
The EWB includes a driving motor for driving the wedge member, a screw shaft coupled with a rotating shaft of the driving motor, and a pressing member coupled to the screw shaft such that the pressing member can move back and forth according to the operation of the driving motor to press the wedge member against the disc.
In such a disc brake, as the driving motor operates, the pressing member presses the wedge member against the disc, so that the friction pad makes contact with the disc. At the same time, the wedge member further presses the friction pad against the disc while moving along an oblique side, so that the braking action is achieved.
However, in this case, the moment is generated due to the friction so that the friction pad may be urged to the disc, thereby causing the eccentric abrasion to the initial contact part of the friction pad. If the eccentric abrasion occurs continuously, the braking performance of the EWB system may be degraded.